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Old 13th Oct 2017, 5:25 pm   #141
GrimJosef
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

I once had a scientific glassblower make me a very nice rare-gas discharge calibration lamp for a spectrometer I was using. We spent a little while discussing glass-to-metal seals and how tricky it could be getting them to work over a wide range of temperatures without the materials' different thermal expansion coefficients causing the seal to micro-crack. The best results involved tuning the glass's and metal's compositions to work optimally over the device's operating temperature range. I'll bet the seals in valve bases were optimised for, say a range of 0C to 150C or so. Military spec valves might be rated to work from lower temps (high-altitude aircraft) to higher (badly ventilated kit inside hot parts of tanks or ships). But surely they weren't designed to go down to genuine cryo temperatures. I wouldn't want anyone to come crying to me if their precious Mullards faded away after a few years due to cathode degradation by low-level gas ingress. Of course if I had a stock of them and I needed a way of making sure that my customers kept coming back for more then I might well be more enthusiastic .

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Old 13th Oct 2017, 5:31 pm   #142
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Default Re: 'Cable Break In' - I never knew that!

Quote:
Originally Posted by stevehertz View Post
Quote:
Originally Posted by Voxophone View Post
Quote:
Originally Posted by LeakyGrid View Post

This is not dead. The Quad VA-One is available with “audiophile-grade” valves treated by freezing at -300ºF for 48 hours.

Roger
This one is actually true. Spending 48 hours at such a low temperature is ‘character building’ for the tubes (similar to DofE or one of those American military schools). They then go on to be well-rounded/superior sounding members of society/your hi-fi system.

Non-cryo-treated tubes lack perspective and never realise how lucky they are, whereas those which have been to the North Pole are always thankful for the warmth of their filaments.

Very interesting thread by the way.

Liam
Liam, you don't give a single, science or physics based reason why a cry-treated valve is better than an untreated one. I have to say, the use of phrases and words like 'character building', 'well rounded/superior sounding', and 'perspective' are exactly the reason why non-audiophools respond to such claims with phrases such as smoke and mirrors, voodoo and snake oil. I'd love to hear, from you, in your own science based words (not a link to someone else's similar 'beliefs') exactly why cry-treated valves are better? I don't believe they are until I see the proof, although you say quite clearly and knowingly, "This one is actually true". Prove it. And for sure, 'proof' isn't an audiophool telling me that they can hear a difference. I can't speak for everyone (clearly) but in general we're a pretty science based bunch on here, we grew up on electronics and radio theory, and we use that theory every day to repair, set up and even modify audio equipment old and new. Notional views are only of use to those who want to believe them and for whatever reason choose not to look for objective based answers. Then again... you could be joking..
I took Liam's post with a pinch of salt, but now I'm beginning to wonder if he was being serious
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Old 13th Oct 2017, 6:05 pm   #143
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Default Re: 'Cable Break In' - I never knew that!

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Then again... you could be joking..
By no means. The anthropomorphism of valves has been scientifically proven. They really do have little thermionic personalities and benefit from team building exercises.
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Old 13th Oct 2017, 6:20 pm   #144
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

A rule of thumb I use is that if audio equipment needs special cables for input, output or mains supply then there is something deficient in the equipment design. This is the opposite of what many audiophiles believe; they think that cable fussiness is a sign of 'fine discrimination'.

Techniques for keeping out unwanted RF are fairly well-known and not too expensive. Mobile phone signals, for example, are unlikely to make it very far through a typical PSU.
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Old 13th Oct 2017, 7:37 pm   #145
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

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You can always tell an audiophool on a forum by looking at their avatar where their hfi set up is listed. It's usually a collection of weird names (cottage industry one man bands normally) that are hard to pronounce, extremely expensive and very 'prestigious' to those in the know.
Yes, you're right, those lists are a dead give-away.

I think one mark of a true audiophile product is that more effort seems to have gone into the development of the name than of the product.

David
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Old 13th Oct 2017, 7:57 pm   #146
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

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I'll bet the seals in valve bases were optimised for, say a range of 0C to 150C or so. Military spec valves might be rated to work from lower temps (high-altitude aircraft) to higher (badly ventilated kit inside hot parts of tanks or ships). But surely they weren't designed to go down to genuine cryo temperatures.
I'd be rather dubious about subjecting a valve, with its vulnerable glass-metal seals, to cryo temperatures, for tha same reason! I'd hate them to crack... and doing this sort of thing to them is almost as likely to fracture the seal as bouncing them on a marble floor...

Regarding cables and mobile phone pickup, yes most amplifiers have negative feedback which is another way of saying that the output lead is actually connected (albeit via some attenuation) to a fairly sensitive input node. Not surprising that strong RF can get detected! From a design point of view, the series output inductor, if fitted and if suitably wound as a really low capacitance choke, might do double-duty as RF filter as well as a stability-enhancer for capacitive loads.

I have found even a basic 4-valve battery superhet (Vidor CN420a), operating from batteries, responds to mobile phone buzz if the phone is closer than 3 feet. Not tried to find exactly where it's getting in yet, but it's quite surprising!
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Old 13th Oct 2017, 8:34 pm   #147
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

An amusing exchange about power cables occurred on a non-audio-related forum. An individual had purchased a high end home cinema system and had been advised that it would only achieve its potential if a suitable mains supply was laid on for it. It was suggested that a dedicated circuit of minimum 32A rating should be installed as the amplifier was allegedly capable of consuming up to 40A on audio peaks. A particular cable (CY) was recommended, that an electrician then indicated was not approved for UK electrical installation work. Not being a phool, he became suspicious and sought advice before proceeding.

As part of the discussion, I tested my bench monitor system over lunch and found it would run happily, as loud as I could tolerate, on an F315mA fuse provided I bypassed the fuse at switch-on. That included the player, preamp and Quad 520 power amp. I had in mind to test it powered via a 100m roll of CW1308 phone cable and make a spoof video about its beneficial filtering effect for future phool-baiting, but real work beckoned and I had to put the proper fuse back in the plug. Of course, such a test would have failed miserably as I would have neglected to burn-in the cable. Or just possibly I might have burnt it out instead.

To rephrase a point made above: If you can hear the difference between two mains leads, you need to fix your amplifier before using it to compare the sound of mains leads.
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Old 13th Oct 2017, 9:27 pm   #148
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

Lucien, you've just stimulated the idea for a new product... Special adaptors so that mains leads can be used in the reverse direction so that they can be checked in both directions.

Potentially lethal or what?

David
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Old 13th Oct 2017, 11:48 pm   #149
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

When I was with Plessey in the 1970's, the lowest temperature used to test military stuff was minus 30°C, but that was in the transistor/IC era.
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Old 14th Oct 2017, 4:39 am   #150
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

I wouldn't try to defend a lot of the Phoolery that goes on in the audiophile industry, but sometimes I think we should be more forgiving.

For example, in some areas, not so much HiFi, but in the field of instruments and amplifiers, the cable types, and lengths of cables have a very large effect on the frequency response and sound.

One reason for this is the Hi Z output impedances of guitar pickups and the controls used. Since the impedance is high, usually well over 100k depending on the control positions, then the coaxial cables leading to the amplifier have a big effect, a few meters or more can be over 500 to 700pF. So musicians notice this changes the sound. So it becomes common knowledge that "The cable affects the sound" This gets generalized to other scenarios, where the source impedance is very low, and the cable capacitance is now having negligible effects, but it is still assumed "the cable affects the sound" so you can understand why people end up thinking this way.

Long cables between magnetic phono cartridges can also have some high frequency roll off effects.

The world would be wonderful if all signal outputs from every device/instrument were low Z and better still matched to the cable impedances and we could forget about cable characteristics, but that is not reality.

When early electronic effects like treble boost amplifiers were added to guitars, to lift the high frequency harmonics, one method of controlling it was just to put a series 500k pot with the output of the guitar. This formed an LPF with the cable capacitance that the musician could adjust. The effects of this are very significant.

Have a look at the Spice simulations in this article looking at the behavior of a simple single transistor treble boost amplifier that Gretsch fitted to some of their guitars in the 1960's that used this idea, without the cable capacitance it would not work properly:

http://worldphaco.com/uploads/Gretschdoc.pdf

So it must be awfully hard for non technical people to figure out what makes sense, when sometimes a remark about an audio related part, a cable, a valve, a capacitor etc is made and if its likely to be correct or just nonsense.

What is really happening here is that the customers in this industry are being taken advantage of by companies using known marketing techniques to pull the wool over their eyes, it (the marketing claims made) probably should be illegal and we should go easy on the customers.
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Old 14th Oct 2017, 12:28 pm   #151
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

Argus 25's comments have reminded me that I had an example where cable types really did make a difference.

It was several decades ago now, so I don't remember all the details, but it involved connecting a reel to reel tape recorder to a tuner amplifier using a 5-pin DIN to 4 Phono-plug cable. I had an unexpectedly poor treble response which was fixed when I used a different cable. I had several 4-way screened cables, and it turned out that they fell into 2 groups, one group had a capacitance of 100 to 150pF (core to ground), the other group were 500 to 600pF (all cables were similar length). The tuner-amp had high value series resistors to the DIN socket (specified for current drive) and, coupled with the high capacitance cable, produced a very noticeable treble roll-off.

My audio cables still have the labels showing their capacitance so I don't get caught again. The low capacitance cables could easily have justified a higher price! As Argus said, instances like this could support the "cables make a difference" argument, when actually it is a design bug (feature?) of the particular tuner-amp.

Stuart
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Old 14th Oct 2017, 2:20 pm   #152
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

This is a fair point - the DIN standard was responsible for a lot of confusion and the odd cable-affected compatibility issue, and it is a short step from there for the uniniated to be persuaded that audible problems with cables do not allow of a simple explanation. Hence the whole fancy cable thing.

If hi fi kit is properly designed and used, the effect of exotic cables is negligible.

Excess cable length on magnetic cartridges has an effect, agreed, but this is seldom necessary - passive volume controls likewise. A simple understanding of the lumped parameters involved is entirely adequate to avoid pitfalls at audio frequencies.

When it comes to musical instruments, of course, things are different, for the reasons outlined - high and variable sending impedances, indeterminate cable lengths and diverse amplifier designs. Also, a sound is being created, not reproduced. Just look at what goes into making an Ondes Martinot...
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Old 14th Oct 2017, 9:54 pm   #153
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

One important difference between cable capacitance and audiophool effects is that cable capacitance (and inductance, and resistance) can be measured using normal measuring instruments. It is a real property of the cable, there are good theoretical reasons for believing that there should be a measurable capacitance between the core and screen of the cable (for example).

Moreover, it is possible to calculate (or model) the effect of this capacitance (assuming the rest of the circuit is known). No (sane) electronic engineer would dispute that.

And I suspect that if the capacitance causes a significant effect it can be detected in a listening test (although probably not by me )

But most of the audiophool effects have no measurable properties, they have no physical justification and don't seem to be properly detectable in a listening test.
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Old 14th Oct 2017, 11:37 pm   #154
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

The multiplex output from the Beam Echo tuner I restored went directly from the demodulator to a phono socket. As stereo was not being transmitted when it was made I guess they could get away with it, but a simple calculation says it would play havoc with the signal. I added a FET buffer.

I wonder how many buy equipment for other reasons than sounds quality. This definitely applies to speakers where looks often take precedence.

In modern art there is no coloration between skill and effort and the value. In celebrities, none between earnings and abilities. It's a strange world we live in and esoteric cables at least perform a useful function.
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Old 14th Oct 2017, 11:45 pm   #155
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

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Long cables between magnetic phono cartridges can also have some high frequency roll off effects.
Funnily enough, long cables have the opposite effect on a typical MM cartridge. We discussed this a while back in this thread: http://www.vintage-radio.net/forum/s...d.php?t=134895 (see post #13 and onwards)
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Old 15th Oct 2017, 1:18 am   #156
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

Yes, That is true I agree due to resonance effects the cartridge inductance with certain length cables and their exact capacity. But if the capacitive loading is high enough there will be HF roll off too.

In any case, this represents a problem where the output of a device, be it a transducer like a cartridge or microphone or pickup, really has an impedance that is too high and a frequency response profile that can be affected by loading from a real cable, be it resonances or damping. Ideally the turntable cartridge, or a microphone or guitar pickup, or a signal source from any unit would have a buffer in it and drop the output impedance to a sensibly low value prior to driving "the cable" and then we wouldn't have to worry about cable length & capacity issues as much.

In some controlled professional audio work it is attended to with 600 Ohm systems and balanced lines too, but in a lot of audio equipment and especially with instruments like guitars a lot less attention is paid to the issue so people start noticing the effects of the cables, and generalizing those experiences to every other situation involving a cable.
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Old 15th Oct 2017, 8:06 am   #157
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

I think we need to pull back a frame or two and remember that there are rather basic, 'sensible' things to remember when considering cables eg that in certain circumstances you have to pay 'attention to' their capacitance and their shielding capabilities. There's other factors too, for sure, but those two are the main ones that are likely to affect the sound - in certain circumstances.

But this 'sensible', and for want of a better word, scientific approach is a million miles away from the audiophool type of thing where all manner of non-scientific, no-proven phrases and words are used to justify a ridiculously high price for cables that in truth offer no real benefits and again, in truth, sound no different to decent, good quality ones that can be bought for a few pounds.

So just because we're talking about cables that have (say) too much capacitance, it doesn't mean that the only alternative is an esoteric, audiophool version that costs a small mortgage; lower capacitance cables are readily available in the normal price range of 'non-esoteric' cables.
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Old 15th Oct 2017, 9:18 am   #158
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

Back in the day, I wasn't aware that the capacitance of the 4-way audio cables was specified on the packaging. And even if it was, would folk appreciate the benefit of the low capacitance, or could smart marketing (or "experts") convince people that more is better, "more capacitance to handle the complexities of the music" or some such baseless claim.

I once read a review of a CD player in what I thought was a respectable magazine which made the claim that this particular player had cleaner bass because in had a die cast chassis....

Stuart
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Old 15th Oct 2017, 9:19 am   #159
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

Applying logic: (dangerous, I know...)

If wire makes a difference and what comes out of one can't be 'better' than what went in the other end, then the best wires are no wires. All the electronics, the tuner, turntable etc should be in the same box.

We're back to the music centre!

But then there are the speaker cables... So the speakers have to go in the box, too. Those audiophiles who treat 'interconnects' as more important than the things they interconnect should never have left the radiogram era.

They've already bought up all the pre-war triodes, so they just need to fight over the remaining radiogram carcasses to put them back in.

glorious sound?...................tick
valved?............................. tick
rare?................................ tick
absolutely digital-free?....... tick
impressively expensive?......soon will be!

We just need an audiophool-acceptable pundit to explain it to them in their language.

What goes around, comes around.

David
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Old 15th Oct 2017, 11:17 am   #160
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Default Re: Audiophoolery. 'Cable Break In' - I never knew that!

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Back in the day, I wasn't aware that the capacitance of the 4-way audio cables was specified on the packaging. And even if it was, would folk appreciate the benefit of the low capacitance, or could smart marketing (or "experts") convince people that more is better, "more capacitance to handle the complexities of the music" or some such baseless claim.

I once read a review of a CD player in what I thought was a respectable magazine which made the claim that this particular player had cleaner bass because in had a die cast chassis....

Stuart
When I made up the cabling for MP3/CD to a valve amplifier I put the loading resistors for the 30 ohm in the jack plugs at the amplifier end of the cable. It is common practice to match a cable run at the destination.

If the CD player has to have a cast chassis then the amplifier also needs a cast chassis.
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